1. Bring a large pot of salted water to a boil. Add the rotini pasta and cook according to the package instructions until al dente. Drain and rinse under cold water to stop the cooking process.
2. While the pasta cooks, heat a grill pan over medium-high heat. Brush the corn with olive oil and grill until charred, about 8-10 minutes, turning occasionally. This step adds a smoky flavor reminiscent of traditional street corn.
3. Once cool enough to handle, cut the kernels off the cob and place them in a large mixing bowl.
4. Add the cooked pasta, cherry tomatoes, red onion, and cilantro to the bowl with the corn.
5. In a separate small bowl, whisk together the mayonnaise, sour cream, lime juice, chili powder, salt, and pepper to create the dressing.
6. Pour the dressing over the pasta mixture and toss until everything is well coated and combined.
7. Sprinkle the crumbled cotija cheese over the top before serving.

Pro tip: Prep the dressing in advance and store it in the fridge. This little hack has saved me on more than one hectic evening!